The new brown cultivar, Agaricus bisporus ’Okhyang’, was developed by the Chungcheongnam-do Agricultural Research and Extension Services with the goal of generating a cultivar suited to the domestic cultivation environment and superior to previously developed cultivars. The ‘Okhyang’ cultivar was selected through basidiospore crossbreeding between ‘CM021735’ and ‘CM021812’, exhibiting faster mycelial growth (58 mm) and darker cap color than the reference cultivar ‘Dahyang’ (53 mm) after 15 days at 25 oC. Furthermore, the cultivar may have an advantage in distribution owing to its more uniform cap shape and firmer fruiting body. Individual fruiting body weight and yield were 41.8 g and 11.2 kg/m2, respectively, which were approximately 9.8% higher than those of ‘Dahyang’. Therefore, ‘Okhyang’ cultivar can potentially increase income for button mushroom farmers and enhance consumer preference.